Interface methods java abstract -

is true interface's methods abstract must override them? thanks. can't remember if interfaces abstract , require override. thank you.

leaving out new stuff introduced in java 8 complicates question, yes interface methods abstract. if have interface this...

public interface someinterface {     public void methodone();     public void methodtwo(); } 

then class not compile.

public class someclass implements someinterface {  } 

the code not compile because someclass not provide implementation of methods defined in someinterface.

the following class compile because provides implementatsion of interface methods.

public class someclass implements someinterface {     public void methodone() {         // ...     }      public void methodtwo() {         // ...     } }